Anybody have any suggestion or recommendations about how best to protect yourself if you decide to give (sell) rights to one of your images to a painter? In this case, it is an oil painter who wants to use an image as a source document for a painting. He could sell the paintings, sell prints of the paintings, license other use, ie for advertising or marketing purposes.
Is there a good standard contract?
What are the important considerations?
What might be a reasonable selling price for the image?
Any reason not to limit rights?

Anybody have any suggestion or recommendations about how best to protect yourself if you decide to give (sell) rights to one of your images to a painter? In this case, it is an oil painter who wants to use an image as a source document for a painting. He could sell the paintings, sell prints of the paintings, license other use, ie for advertising or marketing purposes.
Is there a good standard contract?
What are the important considerations?
What might be a reasonable selling price for the image?
Any reason not to limit rights?

You mean "license" some rights. Correct. lol

IMHO, you need to put in the invoice/contract, exactly what he will be doing with your image.

Is he making one Painting and that is all;
or is he printing Limited Edition Prints and selling those also; How many? What cost?
or is he making "Cards" and selling them also;
or does he plan on making an unlimited number of "posters";
or does he intend to use the finished painting in a "book" that he intends to sell;
and if he does, will he be making Advertisements as sell sheets with your image;
well, you get the idea.

Then there is the possibility that he might want to just pay you "royalties", AFTER he sells whatever things he will be selling. But you would really need to trust him, or have access to his books. Which is something that nobody likes.

The reason, I included all those "other" sales options above is because I do have a little experience with an Nationally Known Artist using two of my images for a painting and a Limited Edition Print run, WITHOUT my permission or knowledge.

After I sued him for "Copyright Infringement", I learned a lot about "professional" artists and how some of them, (at least how he did it) made their "real" money.

It was NOT the huge Five Foot Tall Watercolor Painting he painted and sold. But the "almost" ( it has been many years ago) 2,000 Limited Edition Prints that he sold. Even back then, the "Retail" price for a LE Print from him, was $80. But, honestly he sold a lot at 1/2 off for "wholesalers" price and some at an even lower "dealers" price. But he "still" made a lot of money from the LE Prints.

So just be careful, not to get used. I used to absolutely go nuts when I would read articles about how great of an artist he was because he really captured he "spirit and character" of the birds he painted!!!! Arrrggghhh... He did NOT do that. I did that! He just used an artist projector to copy my images, feather by feather. lol Sorry for the rant. It still gets to me. lol